Parametric information translating system



Feb. 27, 1968 3,371,217

PARAMETRIC INFORMATION TRANSLATING SYSTEM w. E. FLANNERLY ET L med March 5. 1964 ll m2: Jwn

- INVENTORS WILLIAM E. FLANNERY mumnom wmJbm mwwmzmk THOMAS J. MATCOVICH ATTORNEY msm On 6 wumaOm EDA O a with its construction and mode of United States Patent 3,371,217 PARAMETRIC INFORMATION TRANSLATING SYSTEM William E. Fiannery, Norristown, and Thomas J. Mateovich, Maple Glen, Pa., assignors t Sperry Rand Corporation, New York, N.Y., a corporation of Delaware Filed Mar. 5, 1964, Ser. No. 349,549 11 Claims. (Cl. 30788) This invention relates to information translating systems, and, in particular, relates to such systems which utilize parametrically operated devices.

This invention preferably utilizes parametircally operated devices such as those described in United States patent application Serial No. 201,169, entitled Information Handling Devices, by William E. Flannery, filed June 8, 1962, and assigned to the common assignee of this application.

The information handling devices as described in the aforementioned application utilize substrates having a thin anisotropic magnetic film deposited thereon. An alternating current pump source and DC. bias source are coupled to the hard axis of the film to alternately cause the magnetic state of the film to be switched from one hard direction to the other. Normally, the magnetic state of the film is switched by the process of noncoherent fall back. An output winding, coupled to the easy axis of the film, is tuned with a capacitor to be resonant at one-half the frequency of the pump source when the magnetic state of the film lies along the easy axis. A trigger winding is coupled to the film whose axis preferably lies at an angle from to 40 degrees with the hard axis. Upon application of a suitable tri ger pulse, the magnetic state of the film is displaced away from the hard axis, and hence, due to the pump source, the magnetic state of the film oscillates by the process of coherent fallback. The inductance of the magnetic film, as seen by the output winding, varies. Hence, an input signal, applied to the output winding, having a frequency equal to one-half the pump frequency, is parametrically amplified.

In the past, parametrically operated devices, such as those devices known in the art as the parametron, have been coupled together insuccessive stages as shift registers, logical AND gates, OR gates, majority circuit gates and the like. The various stages have had a clocked threephase pump source applied thereto. The three-phase pump source was used in order to assure that information flowed in a unidirectional manner.

In accordance with one embodiment of this invention, parametric devices of the type described by Flannery supra are coupled together in successive stages. A singlephase pump source is applied to all the stages simultaneously. Timed trigger pulses are applied successively to the various stages.

Therefore, it is an object of this invention to provide a parametrically operated multiple-stage system which eliminates the necessity for a three-phase pump source.

Another object of this invention is to provide a relatively inexpensive unidirectional parametric translating circuit.

Other objects and advantages of this invention, together operation, will best be understood from the following description, when read in conjunction with the accompanying drawings in which like reference numerals refer to like components and in which:

FIG. lis a diagram, partly in cross-section, of one embodiment of this invention;

FIG. 2a is a waveform of a trigger pulse in accordance with one embodiment of this invention; and

FIG. 2b is a waveform of other trigger pulses in accordance with another embodiment of this invention.

" 3,371,217 Cfi Patented F eb. 27, 1968 Referring to FIG. 1, there are shown three separate stages labeled A, B, and C. At each stage, there is shown an anisotropic thin magnetic film 10 deposited upon a suitable substrate 12. These magnetic films can be produced by various methods including electrodeposition and vacuum deposition. Anisotropic magnetic films can be produced by depositing a film of ferromagnetic alloy onto the substrate in the presence of a magnetic field. Such a film possesses an easy magnetic axis in one direction, remaining magnetically stable in that aligned direction. When a magnetic field of sufiicient magnitude is applied to an anisotropic film along its hard axis, the direction of the magnetization is brought into alignment with the applied field; however, as the applied magnetic field is quickly reduced to zero, the magnetization of the film becomes unstable, tending to return to the easy magnetic axis by one of tWo ways: coherent fallback or noncoherent fallback. Coherent fallback occurs when the magnetization rotates coherently from the hard axis to the easy axis. In the process of noncoherent fallback, no uniform rotation of the magnetization occurs but reversal occurs by other means. Experimentally, it has been found that when a film has a magnetic field applied to its hard direction, usually, upon removal of the field, the film tends to fallback noncoherently (without rotation). However, by displacing the effective magnetic moment away from the hard axis an angle in excess of 10 degrees, as by a control pulse applied to a separate winding, coherent fallback occurs and rotation of the magnetic field takes place.

A pump source 14 is coupled to a separate pump winding 16 for each of the three stages, each pump winding having its main axis lying parallel to the hard axis of its respective film. The pump source 14 includes a DC. bias and an A.C. supply having a frequency f superimposed on the D.C. bias. The DC. bias is of sufiicient magnitude to create a magnetic field H which is greater than H the field to be overcome to saturate the film in the hard direction. The peaks of the A.C. supply are of such value to create a magnetic field which is equal to or greater than two times H A control winding 18 having its axis oriented approximately 40 degrees from the hard axis (for each of the three stages, respectively) receives suitable trigger pulses from a trigger source 26, the trigger pulses being applied in a timed relation to each of the trigger windings 13 for the stages A, B, and C. The timed relation can be provided as shown in FIG. 1 by applying the trigger source 20 to a delay line 32 which has individual taps for supplying the individual trigger windings 18 of the three stages A, B, and C, respectively.

An output Winding 22 is coupled to the easy axis of the film 1%). Each ouput winding 22 has a capacitor 24 across its terminals so that the resonant frequency of the output circuit, with air inductance, is f /Z for each of the three stages A, B, and C. A signal source 28 is coupled by suitable means, such as a transformer 30, to the output tuned circuit 22, 24 of the A stage. The output of the A stage is coupled to the output tuned circuit 22, 24 of the B stage by means of a separate transformer 36 Similarly, the output of the B stage is coupled by another transformer 30' to the output tuned circuit 22, 24 of the C stage. The output of the C stage is coupled by suitable means, such as a transformer, to subsequent stages or (as shown in FIG. 1) to a suitable load 26.

The signal source 28 has a frequency f,,/ 2, and is produced, preferably in one of two different phase relationships. The signal source can be provided from suitable oscillating circuits.

In the absence 'of an external signal, the magnetic state of the film 10 is alternately switched from saturation in the hard direction to saturation in the opposite hard direction by noncoherent fallback. However, by

applying a suitable trigger pulse to the trigger winding 18, the magnetic state of the film rotates and oscillates by coherent fallback wherein the inductance of the output winding 22 is varied. Signals applied to the output winding are amplified parametrically as set forth in greater detail by Flannery supra.

Generally, parametric devices are biterminal devices which have no directionality. This shortcoming has been overcome in the prior art by the use of equipment that provides a three-phase pump source, which equipment is relatively complicated and expensive. However, by practicing the teachings of this invention, the require ment for a three-phase pump source is eliminated.

Referring again to FIG. 1, the pump source 14 is applied to each of the parametric stages A, B, and C, continuously. All the parametric stages are biased to the Off condition using the techniques taught in the Plannery application. Referring to FIG. 2a, a trigger pulse is instituted by the trigger pulse source which pulse is of such duration with respect to the delay times in the parametric stages, that it simultaneously biases one stage or two adjacent parametric stages into an On condition. In operation, a pulse puts the parametric stage A into the On condition, and, then, while the A stage remains On, the B stage is also biased into the On condition. As the biasing pulse moves along the delay line 32, the A stage reverts to the Off condition and, a short time later, the C stage is biased to the On condition while the B stage remains in the On condition. Consequently, a signal passes directionally from A to B to C. After the bias pulse passes the B stage and the B stage reverts to the Oii condition, the next pulse (not shown) places the A stage in the On condition while C is still in the On condition. By this technique, a signal is transmitted in the forward direction only (from left to right, as viewed). It is not necessary to pulse the pump source or to use a phased pump. A clocked source can be used to provide the trigger pulse for maintaining the desired timing in the overall system.

An alternate embodiment of this invention utilizes the trigger pulses as shown in FIG. 2b to make fuller use of the Flannery device as described heretofore. Note that a negative bias is always present in the embodiment shown in FIG. 2a, but that, in the embodiment shown in FIG. 2b, the bias is eliminated and the pulses shown in FIG. 2b are substituted for that shown in FIG. 2a. The spacing between pulses shown in FIG. 2b is equal to the duration of the pulse shown in FIG. 2a.

When the first (positive) pulse as shown in FIG. 2b is applied to the trigger winding 18 of a parametric stage, placing the stage in an oscillating condition, the oscillation continues when the positive bias is removed. The negative bias pulse terminates the oscillations, in the film of that particular stage, as described in detail in the aforementioned Flannery application. After the negative pulse biases the parametric stage to an Off con- .dition, it remains off, even though the bias pulse is removed and stays off until a subsequent positive bias pulse is applied. The operation of the embodiments using the pulses shown in both FIGS. 2a and 2b are similar.

In general, with a delay time d, between stages, the time t for the duration of a pulse for the embodiment of FIG. 2a or between a positive pulse and negative pulse for the embodiment of FIG. 2b should be such that The time T between the leading edge of subsequent positive levels should be such that 2d T (2d+t).

Preferably, T=2t=3d relationship should be attained. The embodiments of the invention in which an exelusive property or privilege is claimed are defined as follows:

1. In combination a first, a second, and a third parametric device;

each of said devices adapted to be activated by a control signal of one polarity and deactivated by a control signal of an opposite polarity;

each of said devices adapted to oscillate in one phase or a second phase when activated;

a signal source for providing signals in said one phase or said second phase;

means coupling said signal source to said first device;

means coupling said first device to said second device;

means coupling said second device to said third device;

means coupling said third device to an output circuit;

a control source for providing alternately control signals of said one polarity and control signals of said opposite polarity; and

means for coupling said control signals to said first,

second, and third parametric devices in a timed manner.

2. The combination as claimed in claim 1 wherein said control signals are sequentially provided to said first, second, and third devices, in the order named, with a time delay d between adjacent devices; wherein the time elapsed between a signal of said one polarity and the subsequent signal of said opposite polarity'is the duration r; and wherein the time elapsed between a signal of said one polarity and a subsequent sequence of said one polarity is the time T, and wherein 3. The combination as claimed in claim 2 wherein T=3d.

4. The combination as claimed in claim 2 wherein T=2t=3d.

5. In combination,

a first, a second, and a third anisotropic thin magnetic film, each having an easy axis and a hard axis of magnetization;

means for receiving a pumping source having an alternating current voltage at a frequency f a first, a second, and a third pump Winding, all coupled to said receiving means, and each inductively coupled to the hard axis of said first, said second, and said third film respectively;

means for receiving voltage levels from a control source;

means coupled to said receiving means, having a first, a second, and a third set of terminals, for providing varying voltage levels to said terminals in a timed manner;

a first, a second, and third control winding coupled to said first, said second, and said third set of terminals, respectively, each of said control windings, one respectively for each one said film, being coupled to an axis in its respective film which lies at an angle in excess of 10 with respect to its hard axis;

a first, a second, and a third output winding inductively coupled, respectively, to the easy axis of said first, said second, and said third films, respectively, each of said output windings when its respective film is magnetized in its easy direction having an inductance o;

a first, a second, and a third capacitor C coupled, re-

spectively, across said first, said second, and said third output winding, respectively,

the values of L and C being such as to be resonant at approximately f 2;

means for receiving a locking signal having a frequency fin means for coupling said locking signal receiving means to said first output'winding;

means for coupling said first output winding to said second output winding;

means for coupling said second output winding to said third output winding; and

means for coupling said third output winding to an output circuit.

6. The combination as claimed in claim wherein said voltage levels are alternately of two types and are sequentially provided to said first, second, and third devices, in the order named, with a time delay d between adjacent devices; wherein the time elapsed between the leading edge of a level of one type and the leading edge of a subsequent level of the other type is the duration If; and wherein the time elapsed between the leading edge of a level of said one type and a subsequent level of said one type is the time T, and wherein 7. The combination as claimed in claim 6 wherein T =3a'.

8. The combination as claimed in claim 6 wherein T -2f=3d.

9. In combination,

a first anisotropic thin magnetic film having an easy axis and a hard axis of magnetization;

a second anisotropic thin magnetic film having an easy axis and a hard axis of magnetization;

a third anisotropic thin magnetic film having an easy axis and a hard axis of magnetization;

a first pump winding inductively coupled to said first film hard axis;

a second pump Winding inductively coupled to said second film hard axis;

a third pump winding inductively coupled to said third film hard axis;

a direct current bias source coupled to said first pump winding, said second pump winding, and said third pump winding, said source being of sufiicient magnitude to saturate each of said films in one direction along its respective hard axis;

an alternating current pump source coupled to each of said pump windings, said pump source having a frequency f and a peak voltage equal to at least twice said bias source whereby each of said films can alternately be saturated in opposite directions along its respective hard axis, the reversal of magnetic saturation normally occurring in a. non-coherent manner;

a control voltage source;

distribution means coupled to said control voltage source for providing control voltages in a timed distributive manner;

a first control winding coupled to said distribution means and inductively coupled to said first film, a second control winding coupled to said distribution means and inductively coupled to said second film, and a third control winding coupled to said distribution means and inductively coupled to said third film, each of said control windings being coupled to its respective film at an angle with respect to its respective hard axis, said angle and said control voltage being of such values that a magnetic moment is created in the respective film temporarily to cause saturation in a direction displaced from its respective hard axis, whereby the reversal of saturation by the respective film takes place coherently;

a first output winding coupled inductively to said first film easy axis, said first output winding having an inductance, when said first film is saturated in its easy direction, of L a second output winding coupled inductively to said second film easy axis, said second output winding having an inductance, when said second film is saturated in its easy direction, of L a third output winding coupled inductively to said third film easy axis, said third output winding having an inductance, when said third film is saturated in its easy direction of L a first capacitor C coupled to said inductance L said C forming a first tuned circuit resonant at f /2;

a second capacitor C coupled to said inductance L said L and C forming a second tuned circuit resonant at f /Z;

a third capacitor C coupled to said inductance L said L and C forming a third tuned circuit resonant at J n means for coupling a locking signal at frequency f /2 to said first output winding;

means coupling said first tuned tuned circuit;

means coupling said second tuned circuit to said third tuned circuit; and

means for coupling said third tuned circuit to an output circuit.

10. The combination as claimed in claim 9 wherein said control voltage source provides voltage potentials of alternating polarity and wherein said potentials are scquentially provided to said first, said second, and said third films, in the order named, with a time delay d between successive films; wherein the time elapsed between a signal of said one polarity and the subsequent signal of said opposite polarity is the duration t; and wherein the time elapsed between a signal of said one polarity and a subsequent sequence of said one polarity is the time T, and

wherein circuit to said second 11. The combination as claimed in claim 10 wherein T =2t=3d.

TERREL W. FEARS, Primary Examiner. BERNARD KONICK, Examiner. 

1. IN COMBINATION A FIRST, A SECOND, AND A THIRD PARAMETRIC DEVICE; EACH OF SAID DEVICES ADAPTED TO BE ACTIVATED BY A CONTROL SIGNAL OF ONE POLARITY AND DEACTIVATED BY A CONTROL SIGNAL OF AN OPPOSITE POLARITY; EACH OF SAID DEVICES ADAPTED TO OSCILLATE IN ONE PHASE OR A SECOND PHASE WHEN ACTIVATED; A SIGNAL SOURCE FOR PROVIDING SIGNALS IN SAID ONE PHASE OR SAID SECOND PHASE; MEANS COUPLING SAID SIGNAL SOURCE TO SAID FIRST DEVICE; MEANS COUPLING SAID FIRST DEVICE TO SAID SECOND DEVICE; MEANS COUPLING SAID SECOND DEVICE TO SAID THIRD DEVICE; MEANS COUPLING SAID THIRD DEVICE TO AN OUTPUT CIRCUIT; A CONTROL SOURCE FOR PROVIDING ALTERNATELY CONTROL SIGNALS OF SAID ONE POLARITY AND CONTROL SIGNALS OF SAID OPPOSITE POLARITY; AND 